The present invention relates generally to multi-piece tool and, more particularly, to such tools having an arrangement for distributing securing forces between components of the tool.
Many modern cutting tools use replaceable cutting inserts made of an extremely hard material such as cemented carbide. The inserts can be mounted on toolholders or shanks made of more conventional and more easily machined materials that are typically less hard but also less brittle than the inserts. In the sense used here, brittle means that the inserts may have a Young's modulus about six times that of conventional steel. Care must be taken in the use of such inserts to avoid breakage.
It is desirable to provide a multi-piece tool assembly, particularly a cutting tool assembly, having male and female threaded components wherein the risk of damage to the female component during tightening can be reduced.
In accordance with an aspect of the present invention, a multi-piece tool assembly comprises a male threaded member having an external thread, and a female threaded member having an opening adapted to receive at least part of the male threaded member up to a predetermined depth and an internal thread adapted to mate with the external thread of the male threaded member. When the male threaded member is received in the opening to the predetermined depth, substantially all forces between the external thread and the internal thread are oriented along an axis of the female threaded member, a working portion of the tool assembly being provided on one of the male threaded member and the female threaded member.
In accordance with another aspect of the present invention, a cutting tool comprises a female threaded member having an opening adapted to receive at least part of a male threaded member up to a predetermined depth and an internal thread adapted to mate with an external thread of the male threaded member, a force-bearing flank of the internal thread extending substantially perpendicular to an axis of the female threaded member, and a working portion of the tool provided on the female threaded member.
In accordance with another aspect of the present invention, a cutting tool, comprises a male threaded member having an external thread, the male threaded member being adapted to be at least partially received in an opening of a female threaded member up to a predetermined depth, the external thread being adapted to mate with an internal thread of the female threaded member, a force-bearing flank of the external thread extending substantially perpendicular to axes of the male threaded member and the female threaded member, and a working portion of the tool assembly being provided on the male threaded member.